Magnetic head and magnetic recording device

ABSTRACT

According to one embodiment, a magnetic head includes a shield, a magnetic pole, a first magnetic layer provided between the shield and the magnetic pole, a second magnetic layer provided between the first magnetic layer and the magnetic pole, a third magnetic layer provided between the second magnetic layer and the magnetic pole, a first nonmagnetic layer provided between the shield and the first magnetic layer, a second nonmagnetic layer provided between the first magnetic layer and the second magnetic layer, a third nonmagnetic layer provided between the second magnetic layer and the third magnetic layer, and a fourth nonmagnetic layer provided between the third magnetic layer and the magnetic pole. The first and third nonmagnetic layers include one of Cu, Ag, Au, Al, and Ti. The second and fourth nonmagnetic layers include one of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2019-043930, filed on Mar. 11, 2019; theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a magnetic head and amagnetic recording device.

BACKGROUND

Information is recorded in a magnetic recording medium such as a HDD(Hard Disk Drive) or the like by using a magnetic head. It is desirableto increase the recording density of the magnetic head and the magneticrecording device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view illustrating a magnetic headand a magnetic recording device according to a first embodiment;

FIG. 2 is a schematic cross-sectional view illustrating the magnetichead and the magnetic recording device according to the firstembodiment;

FIG. 3 is a schematic cross-sectional view illustrating a magnetic headand a magnetic recording device according to a second embodiment;

FIG. 4 is a schematic cross-sectional view illustrating the magnetichead and the magnetic recording device according to the secondembodiment;

FIG. 5 is a schematic cross-sectional view illustrating a magnetic headand a magnetic recording device according to a third embodiment;

FIG. 6 is a schematic cross-sectional view illustrating the magnetichead and the magnetic recording device according to the thirdembodiment;

FIG. 7 is a schematic cross-sectional view illustrating the magnetichead and the magnetic recording device according to the embodiment;

FIG. 8 is a schematic cross-sectional view illustrating the magnetichead and the magnetic recording device according to the embodiment;

FIG. 9 is a schematic perspective view illustrating a portion of themagnetic recording device according to the embodiment;

FIG. 10 is a schematic perspective view illustrating the magneticrecording device according to the embodiment; and

FIG. 11A and FIG. 11B are schematic perspective views illustrating aportion of the magnetic recording device according to the embodiment.

DETAILED DESCRIPTION

According to one embodiment, a magnetic head includes a shield, amagnetic pole, a first magnetic layer provided between the shield andthe magnetic pole, a second magnetic layer provided between the firstmagnetic layer and the magnetic pole, a third magnetic layer providedbetween the second magnetic layer and the magnetic pole, a firstnonmagnetic layer provided between the shield and the first magneticlayer, a second nonmagnetic layer provided between the first magneticlayer and the second magnetic layer, a third nonmagnetic layer providedbetween the second magnetic layer and the third magnetic layer, and afourth nonmagnetic layer provided between the third magnetic layer andthe magnetic pole. The first nonmagnetic layer and the third nonmagneticlayer include at least one selected from the group consisting of Cu, Ag,Au, Al, and Ti. The second nonmagnetic layer and the fourth nonmagneticlayer include at least one selected from the group consisting of Ta, Pt,Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru. Thicknesses along a first directionof the second nonmagnetic layer and the fourth nonmagnetic layer eachare not less than 1 nm and not more than 3 nm. The first direction isfrom the shield toward the magnetic pole.

According to another embodiment, a magnetic head includes a shield, amagnetic pole, a first magnetic layer provided between the shield andthe magnetic pole, a second magnetic layer provided between the shieldand the first magnetic layer, a third magnetic layer provided betweenthe shield and the second magnetic layer, a first nonmagnetic layerprovided between the first magnetic layer and the magnetic pole, asecond nonmagnetic layer provided between the second magnetic layer andthe first nonmagnetic layer, a third nonmagnetic layer provided betweenthe third magnetic layer and the second nonmagnetic layer, and a fourthnonmagnetic layer provided between the shield and the third magneticlayer. The first nonmagnetic layer and the third nonmagnetic layerinclude at least one selected from the group consisting of Cu, Ag, Au,Al, and Ti. The second nonmagnetic layer and the fourth nonmagneticlayer include at least one selected from the group consisting of Ta, Pt,Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru. Thicknesses along a first directionof the second nonmagnetic layer and the fourth nonmagnetic layer eachare not less than 1 nm and not more than 3 nm. The first direction isfrom the shield toward the magnetic pole.

According to another embodiment, a magnetic head includes a shield, amagnetic pole having a medium-opposing surface, a first magnetic layer,a second magnetic layer, a third magnetic layer, a first nonmagneticlayer, a second nonmagnetic layer, a third nonmagnetic layer, a fourthnonmagnetic layer, a fifth nonmagnetic layer, and a sixth nonmagneticlayer. A first direction from the shield toward the magnetic pole isalong the medium-opposing surface. A position in the first direction ofthe first magnetic layer is between a position in the first direction ofthe shield and a position in the first direction of the magnetic pole.The second magnetic layer is provided between the shield and themagnetic pole. A position of the second magnetic layer in a seconddirection is between a position in the second direction of the firstmagnetic layer and a position in the second direction of a planeincluding the medium-opposing surface. The second direction crosses themedium-opposing surface. The third magnetic layer is provided betweenthe second magnetic layer and the magnetic pole. The first nonmagneticlayer is provided between the first magnetic layer and the magneticpole. The second nonmagnetic layer is provided between the shield andthe second magnetic layer. The third nonmagnetic layer is providedbetween the second magnetic layer and the third magnetic layer. Thefourth nonmagnetic layer is provided between the third magnetic layerand the magnetic pole. The first magnetic layer is provided between thefifth nonmagnetic layer and the first nonmagnetic layer. The sixthnonmagnetic layer is provided between the second nonmagnetic layer andthe second magnetic layer.

According to another embodiment, a magnetic head includes a shield, amagnetic pole having a medium-opposing surface, a first magnetic layer,a second magnetic layer, a third magnetic layer, a first nonmagneticlayer, a second nonmagnetic layer, a third nonmagnetic layer, a fourthnonmagnetic layer, a fifth nonmagnetic layer, and a sixth nonmagneticlayer. A first direction from the shield toward the magnetic pole isalong the medium-opposing surface. A position in the first direction ofthe first magnetic layer is between a position in the first direction ofthe shield and a position in the first direction of the magnetic pole.The second magnetic layer is provided between the shield and themagnetic pole. A position of the second magnetic layer in a seconddirection is between a position in the second direction of the firstmagnetic layer and a position in the second direction of a planeincluding the medium-opposing surface. The second direction crosses themedium-opposing surface. The third magnetic layer is provided betweenthe shield and the second magnetic layer. The first nonmagnetic layer isprovided between the first magnetic layer and the magnetic pole. Thesecond nonmagnetic layer is provided between the second magnetic layerand the magnetic pole. The third nonmagnetic layer is provided betweenthe third magnetic layer and the second magnetic layer. The fourthnonmagnetic layer is provided between the shield and the third magneticlayer. The first magnetic layer is provided between the fifthnonmagnetic layer and the first nonmagnetic layer. The sixth nonmagneticlayer is provided between the second magnetic layer and the secondnonmagnetic layer.

According to another embodiment, a magnetic recording device includesthe magnetic head according to any one of the above, and a circuitportion. The circuit portion includes a first circuit configured tosupply a first current having an orientation from the first magneticlayer toward the first nonmagnetic layer, and a second circuitconfigured to supply a second current having an orientation from thesecond nonmagnetic layer toward the fourth nonmagnetic layer. Thecircuit portion is configured to control the first current and thesecond current independently from each other.

According to another embodiment, a magnetic recording device includes ashield, a magnetic pole, a first magnetic layer provided between theshield and the magnetic pole, a second magnetic layer provided betweenthe first magnetic layer and the magnetic pole, a third magnetic layerprovided between the second magnetic layer and the magnetic pole, afirst nonmagnetic layer provided between the shield and the firstmagnetic layer, a second nonmagnetic layer provided between the firstmagnetic layer and the second magnetic layer, a third nonmagnetic layerprovided between the second magnetic layer and the third magnetic layer,a fourth nonmagnetic layer provided between the third magnetic layer andthe magnetic pole, and a circuit portion. The circuit portion includes afirst circuit and a second circuit. The first circuit is configured tosupply a first current having an orientation from the first nonmagneticlayer toward the second nonmagnetic layer. The second circuit isconfigured to supply a second current having an orientation from thesecond nonmagnetic layer toward the fourth nonmagnetic layer. Thecircuit portion is configured to control the first current and thesecond current independently from each other.

According to another embodiment, a magnetic recording device includes ashield, a magnetic pole, a first magnetic layer provided between theshield and the magnetic pole, a second magnetic layer provided betweenthe first magnetic layer and the magnetic pole, a third magnetic layerprovided between the first magnetic layer and the second magnetic layer,a first nonmagnetic layer provided between the shield and the firstmagnetic layer, a second nonmagnetic layer provided between the firstmagnetic layer and the third magnetic layer, a third nonmagnetic layerprovided between the third magnetic layer and the second magnetic layer,a fourth nonmagnetic layer provided between the second magnetic layerand the magnetic pole, and a circuit portion. The circuit portionincludes a first circuit and a second circuit. The first circuit isconfigured to supply a first current having an orientation from thefirst nonmagnetic layer toward the second nonmagnetic layer. The secondcircuit is configured to supply a second current having an orientationfrom the fourth nonmagnetic layer toward the second nonmagnetic layer.The circuit portion is configured to control the first current and thesecond current independently from each other.

Various embodiments are described below with reference to theaccompanying drawings.

The drawings are schematic and conceptual; and the relationships betweenthe thickness and width of portions, the proportions of sizes amongportions, etc., are not necessarily the same as the actual values. Thedimensions and proportions may be illustrated differently amongdrawings, even for identical portions.

In the specification and drawings, components similar to those describedpreviously or illustrated in an antecedent drawing are marked with likereference numerals, and a detailed description is omitted asappropriate.

First Embodiment

FIG. 1 is a schematic cross-sectional view illustrating a magnetic headand a magnetic recording device according to a first embodiment.

In the embodiment as shown in FIG. 1, the magnetic recording device 150includes the magnetic head 110 and a magnetic recording medium 80. Themagnetic recording device 150 may further include, for example, arecording current circuit (a third circuit 30D).

The magnetic head 110 includes a shield 31, a magnetic pole 30, first tothird magnetic layers 11 to 13, and first to fourth nonmagnetic layers21 to 24. In the example, the magnetic head 110 further includes a fifthnonmagnetic layer 25 and a sixth nonmagnetic layer 26.

For example, the magnetic head 110 includes a coil 30 c. At least aportion of the coil 30 c opposes the magnetic pole 30. For example, arecording current Iw is supplied to the coil 30 c from the recordingcurrent circuit (the third circuit 30D). Thereby, a recording magneticfield that corresponds to the recording current Iw is generated from themagnetic pole 30. The recording magnetic field is applied to themagnetic recording medium 80; and the orientation of the magnetizationof the magnetic recording medium 80 is controlled. Thereby, informationis recorded in the magnetic recording medium 80.

The magnetic pole 30 is, for example, a major magnetic pole. Themagnetic pole 30 has a medium-opposing surface 30F. The medium-opposingsurface 30F is along the ABS (Air Bearing Surface) of the magnetic head110. The medium-opposing surface 30F opposes the magnetic recordingmedium 80.

A direction perpendicular to the medium-opposing surface 30F is taken asa Z-axis direction. One direction perpendicular to the Z-axis directionis taken as an X-axis direction. A direction perpendicular to the Z-axisdirection and the X-axis direction is taken as a Y-axis direction.

The Z-axis direction is, for example, the height direction. The X-axisdirection is, for example, the down-track direction. The Y-axisdirection is the cross-track direction.

For example, the shield 31 corresponds to a “trailing shield.” Theshield 31 is, for example, an auxiliary magnetic pole. The shield 31 canform a magnetic core with the magnetic pole 30. For example, anadditional shield such as a side shield (not illustrated), etc., may beprovided.

In the magnetic head 110, the first magnetic layer 11 is providedbetween the shield 31 and the magnetic pole 30. The second magneticlayer 12 is provided between the first magnetic layer 11 and themagnetic pole 30. The third magnetic layer 13 is provided between thesecond magnetic layer 12 and the magnetic pole 30.

A direction from the shield 31 toward the magnetic pole 30 is taken as afirst direction D1. For example, the first direction D1 is aligned withthe X-axis direction.

The first magnetic layer 11 includes, for example, at least one selectedfrom the group consisting of FeNi and CoFe. The second magnetic layer 12and the third magnetic layer 13 include, for example, an FeCo alloy,etc. Examples of the materials of these magnetic layers are describedbelow.

The first nonmagnetic layer 21 is provided between the shield 31 and thefirst magnetic layer 11. The second nonmagnetic layer 22 is providedbetween the first magnetic layer 11 and the second magnetic layer 12.The third nonmagnetic layer 23 is provided between the second magneticlayer 12 and the third magnetic layer 13. The fourth nonmagnetic layer24 is provided between the third magnetic layer 13 and the magnetic pole30. The fifth nonmagnetic layer 25 is provided between the firstmagnetic layer 11 and the second nonmagnetic layer 22. The sixthnonmagnetic layer 26 is provided between the second nonmagnetic layer 22and the second magnetic layer 12. The first to third magnetic layers 11to 13 and the first to sixth nonmagnetic layers 21 to 26 are included ina stacked body SB.

The first nonmagnetic layer 21 and the third nonmagnetic layer 23include, for example, at least one selected from the group consisting ofCu, Ag, Au, Al, and Ti. For example, the first nonmagnetic layer 21 andthe third nonmagnetic layer 23 are layers that transmit spin.

The second nonmagnetic layer 22 and the fourth nonmagnetic layer 24include, for example, at least one selected from the group consisting ofTa, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru. The second nonmagnetic layer22 and the fourth nonmagnetic layer 24 are, for example, layers thatquench (or weaken) spin. The thicknesses along the first direction D1 ofthe second nonmagnetic layer 22 and the fourth nonmagnetic layer eachare, for example, not less than 1 nm and not more than 3 nm.

The fifth nonmagnetic layer 25 and the sixth nonmagnetic layer 26include, for example, at least one selected from the group consisting ofCu, Ag, Au, Al, Ti, and Ru. The thicknesses along the first direction D1of the fifth nonmagnetic layer 25 and the sixth nonmagnetic layer 26each are not less than 1 nm and not more than 3 nm. At least one of thefifth nonmagnetic layer 25 or the sixth nonmagnetic layer 26 may beprovided. By these nonmagnetic layers, for example, the increase of thedamping in the first magnetic layer 11 is suppressed. By thesenonmagnetic layers, for example, the increase of the damping in thesecond magnetic layer 12 is suppressed. For example, the operatingcurrent density decreases. For example, a long life is obtained.

As shown in FIG. 1, a first current I1 can flow in the magnetic head110. The first current I1 has an orientation from the shield 31 towardthe magnetic pole 30. The first current has an orientation from thefirst nonmagnetic layer 21 toward the fourth nonmagnetic layer 24. Forexample, the first current I1 is supplied from a first circuit 10D. Forexample, the first circuit 10D is electrically connected to the shield31 and the magnetic pole 30.

The first current I1 flows through the first nonmagnetic layer 21, thefirst magnetic layer 11, the fifth nonmagnetic layer 25, the secondnonmagnetic layer 22, the sixth nonmagnetic layer 26, the secondmagnetic layer 12, the third nonmagnetic layer 23, the third magneticlayer 13, and the fourth nonmagnetic layer 24 in the direction from thefirst nonmagnetic layer 21 toward the fourth nonmagnetic layer 24.

A first electron current Je1 flows due to the first current IL The firstelectron current Je1 flows in an orientation from the magnetic pole 30toward the shield 31.

The magnetic pole 30 has a magnetic pole magnetization 30M. The shield31 has a shield magnetization 31M. The first magnetic layer 11 has afirst magnetic layer magnetization 11M. The second magnetic layer 12 hasa second magnetic layer magnetization 12M. The third magnetic layer 13has a third magnetic layer magnetization 13M.

For example, the first magnetic layer magnetization 11M is reversed withrespect to the shield magnetization 31M and the magnetic polemagnetization 30M by the first current I1 (the first electron currentJe1). Thereby, the recording magnetic field that is generated by themagnetic pole 30 does not pass through the stacked body SB easily. Themagnetic field (the gap magnetic field) between the shield 31 and themagnetic pole 30 can be reduced.

Thereby, much of the recording magnetic field is oriented toward themagnetic recording medium 80. The recording magnetic field is appliedefficiently to the magnetic recording medium 80. For example, the firstmagnetic layer 11 functions as a MFCL (Magnetic Field Control Layer).

On the other hand, spin is injected from the third magnetic layer 13into the second magnetic layer 12 by the first current (the firstelectron current Je1) and the gap magnetic field; and the secondmagnetic layer magnetization 12M rotates. For example, the thirdmagnetic layer 13 functions as a spin injection layer. For example, thesecond magnetic layer 12 functions as an oscillation generation layer.The stacked body that includes the second magnetic layer 12, the thirdnonmagnetic layer 23, and the third magnetic layer 13 functions as, forexample, a STO (Spin Torque Oscillator). For example, spin torque ismutually applied between the second magnetic layer 12 and the thirdmagnetic layer 13. For example, as the current is increased, first, thethird magnetic layer magnetization 13M of the third magnetic layer 13reverses; subsequently, the second magnetic layer magnetization 12M ofthe second magnetic layer 12 starts to oscillate. When the secondmagnetic layer magnetization 12M starts to oscillate, the secondmagnetic layer magnetization 12M oscillates in the orientation of thereverse direction of the third magnetic layer magnetization 13M. Forexample, the second magnetic layer magnetization 12M tilts in the gapmagnetic field direction and oscillates substantially in the plane.

A high frequency magnetic field is generated from the STO; and the highfrequency magnetic field is applied to the magnetic recording medium 80.The orientation of the magnetization changes more easily at the portionof the magnetic recording medium 80 to which the high frequency wave isapplied. The orientation of the magnetization of the magnetic recordingmedium 80 can be controlled easily.

By providing the first magnetic layer 11 in the embodiment, the gapmagnetic field can be reduced without reducing the recording magneticfield. Thereby, for example, the second magnetic layer magnetization 12Mcan be rotated by the spin torque at a low current density. For example,the recording characteristics can be improved thereby. For example, therecording density can be increased. For example, high reliability iseasier to obtain. In the embodiment, a magnetic head and a magneticrecording device can be provided in which the recording density can beincreased.

For example, the gap magnetic field applied to the STO can be controlledby the first magnetic layer 11. For example, the recording magneticfield and the gap magnetic field applied to the STO can be designedindependently. Thereby, for example, the adjustment of the oscillationfrequency of the STO is easy.

FIG. 2 is a schematic cross-sectional view illustrating the magnetichead and the magnetic recording device according to the firstembodiment.

In the embodiment as shown in FIG. 2, the magnetic recording device 150includes a magnetic head 111 and the magnetic recording medium 80. Themagnetic head 111 includes the shield 31, the magnetic pole 30, thefirst to third magnetic layers 11 to 13, and the first to fourthnonmagnetic layers 21 to 24. In the example, the magnetic head 111further includes the fifth nonmagnetic layer 25 and the sixthnonmagnetic layer 26.

In the magnetic head 111, the first magnetic layer 11 is providedbetween the shield 31 and the magnetic pole 30. The second magneticlayer 12 is provided between the shield 31 and the first magnetic layer11. The third magnetic layer 13 is provided between the shield 31 andthe second magnetic layer 12.

The first nonmagnetic layer 21 is provided between the first magneticlayer 11 and the magnetic pole 30. The second nonmagnetic layer 22 isprovided between the second magnetic layer 12 and the first nonmagneticlayer 21. The third nonmagnetic layer 23 is provided between the thirdmagnetic layer 13 and the second nonmagnetic layer 22. The fourthnonmagnetic layer 24 is provided between the shield 31 and the thirdmagnetic layer 13. The fifth nonmagnetic layer 25 is provided betweenthe second nonmagnetic layer 22 and the first magnetic layer 11. Thesixth nonmagnetic layer 26 is provided between the second magnetic layer12 and the second nonmagnetic layer 22.

In such a case as well, the first nonmagnetic layer 21 and the thirdnonmagnetic layer 23 include at least one selected from the groupconsisting of Cu, Ag, Au, Al, and Ti. The second nonmagnetic layer 22and the fourth nonmagnetic layer 24 include at least one selected fromthe group consisting of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru. Thethicknesses along the first direction D1 (the direction from the shield31 toward the magnetic pole 30) of the second nonmagnetic layer 22 andthe fourth nonmagnetic layer 24 each are not less than 1 nm and not morethan 3 nm. The fifth nonmagnetic layer 25 and the sixth nonmagneticlayer 26 include at least one selected from the group consisting of Cu,Ag, Au, Al, Ti, and Ru. The thicknesses along the first direction D1 ofthe fifth nonmagnetic layer 25 and the sixth nonmagnetic layer 26 eachare not less than 1 nm and not more than 3 nm. At least one of the fifthnonmagnetic layer 25 or the sixth nonmagnetic layer 26 may be provided.For example, the increase of the damping in the first magnetic layer 11is suppressed. For example, the increase of the damping in the secondmagnetic layer 12 is suppressed. For example, the operating currentdensity decreases. For example, a long life is obtained.

In the magnetic head 111 as shown in FIG. 2, the first current I1 flowsfrom the magnetic pole 30 toward the shield 31. The first current I1 hasan orientation from the first nonmagnetic layer 21 toward the fourthnonmagnetic layer 24. The first electron current Jet has an orientationfrom the shield 31 toward the magnetic pole 30. The first current I1 issupplied from the first circuit 10D.

In the magnetic head 111 as well, the gap magnetic field can be reducedwithout reducing the recording magnetic field. For example, the secondmagnetic layer magnetization 12M can be rotated by the spin torque at alow current density. For example, the recording characteristics can beimproved. The recording density can be increased. For example, highreliability is easier to obtain. A magnetic head and a magneticrecording device can be provided in which the recording density can beincreased. For example, the adjustment of the oscillation frequency ofthe STO is easy.

In the magnetic heads 110 and 111, for example, the first magnetic layer11 contacts the first nonmagnetic layer 21 and the fifth nonmagneticlayer 25. The second nonmagnetic layer 22 contacts the fifth nonmagneticlayer 25 and the sixth nonmagnetic layer 26. The second magnetic layer12 contacts the sixth nonmagnetic layer 26 and the third nonmagneticlayer 23. The third magnetic layer 13 contacts the third nonmagneticlayer 23 and the fourth nonmagnetic layer 24.

In the magnetic heads 110 and 111, for example, the product of thethickness (the thickness along the first direction D1) of the secondmagnetic layer 12 and a second saturation magnetic flux density of thesecond magnetic layer 12 is larger than the product of the thickness(the thickness along the first direction D1) of the third magnetic layerand a third saturation magnetic flux density of the third magnetic layer13. Thereby, oscillation occurs easily in the second magnetic layer 12.For example, the product of the volume of the second magnetic layer 12and the second saturation magnetic flux density of the second magneticlayer 12 is larger than the product of the volume of the third magneticlayer 13 and the third saturation magnetic flux density of the thirdmagnetic layer 13. For example, the thickness of the third magneticlayer 13 is thinner than the thickness of the second magnetic layer 12.Thereby, for example, stable oscillation is obtained in the secondmagnetic layer 12 and the third magnetic layer 13.

Second Embodiment

FIG. 3 is a schematic cross-sectional view illustrating a magnetic headand a magnetic recording device according to a second embodiment.

In the embodiment as shown in FIG. 3, the magnetic recording device 150includes the magnetic head 120, the magnetic recording medium 80, and acircuit portion 10U. For example, the magnetic recording device 150 mayfurther include a recording current circuit (the third circuit 30D).

The magnetic head 120 includes the shield 31, the magnetic pole 30, thefirst to third magnetic layers 11 to 13, and the first to fourthnonmagnetic layers 21 to 24. In the example, the magnetic head 120further includes the fifth nonmagnetic layer 25 and the sixthnonmagnetic layer 26.

The first magnetic layer 11 is provided between the shield 31 and themagnetic pole 30. The second magnetic layer 12 is provided between thefirst magnetic layer 11 and the magnetic pole 30. The third magneticlayer 13 is provided between the second magnetic layer 12 and themagnetic pole 30.

The first nonmagnetic layer 21 is provided between the shield 31 and thefirst magnetic layer 11. The second nonmagnetic layer 22 is providedbetween the first magnetic layer 11 and the second magnetic layer 12.The third nonmagnetic layer 23 is provided between the second magneticlayer 12 and the third magnetic layer 13. The fourth nonmagnetic layer24 is provided between the third magnetic layer 13 and the magnetic pole30. The fifth nonmagnetic layer 25 is provided between the firstmagnetic layer 11 and the second nonmagnetic layer 22. The sixthnonmagnetic layer 26 is provided between the second nonmagnetic layer 22and the second magnetic layer 12.

The circuit portion 10U includes the first circuit 10D and a secondcircuit 20D. The first circuit 10D is configured to supply the firstcurrent I1. The first current I1 has an orientation from the shield 31toward the second nonmagnetic layer 22. The first current I1 has anorientation from the first nonmagnetic layer 21 toward the secondnonmagnetic layer 22. The second circuit 20D is configured to supply asecond current I2. The second current I2 has an orientation from thesecond nonmagnetic layer 22 toward the magnetic pole 30. The secondcurrent I2 has an orientation from the second nonmagnetic layer 22toward the fourth nonmagnetic layer 24. The orientation of the firstelectron current Je1 based on the first current I1 is the reverse of theorientation of the first current I1. The orientation of a secondelectron current Je2 based on the second current I2 is the reverse ofthe orientation of the second current I2.

For example, the magnetic head 120 includes first to third terminals T1to T3. The first terminal T1 is electrically connected to the shield 31.The second terminal T2 is electrically connected to the magnetic pole30. The third terminal T3 is electrically connected to the secondnonmagnetic layer 22.

One end of the first circuit 10D is electrically connected to the firstterminal T1. The other end of the first circuit 10D is electricallyconnected to the third terminal T3. One end of the second circuit 20D iselectrically connected to the second terminal T2. The other end of thesecond circuit 20D is electrically connected to the third terminal T3.

The first magnetic layer magnetization 11M of the first magnetic layer11 is reversed with respect to the shield magnetization 31M and themagnetic pole magnetization 30M by the first current I1. The secondmagnetic layer magnetization 12M rotates due to the second current I2.The second magnetic layer 12 oscillates.

The circuit portion 10U is configured to control the first current I1and the second current I2 independently from each other. Thereby, theoscillation frequency of the STO can be adjusted easily by the secondcurrent I2 while reducing the gap magnetic field by the first currentI1. The recording density can be increased easily thereby. For example,a magnetic head and a magnetic recording device can be provided in whichthe recording density can be increased.

For example, there are cases where the oscillation frequency of the STOfluctuates due to fluctuation of the manufacturing processes, etc. Insuch a case, the adjustment of the oscillation frequency is easy bycontrolling the first current I1 and the second current I2independently.

In the magnetic head 120, the first nonmagnetic layer 21 and the thirdnonmagnetic layer 23 include, for example, at least one selected fromthe group consisting of Cu, Ag, Au, Al, and Ti. The second nonmagneticlayer 22 and the fourth nonmagnetic layer 24 include, for example, atleast one selected from the group consisting of Ta, Pt, Ir, W, Mo, Cr,Tb, Rh, Pd, and Ru. The thicknesses along the first direction D1 (thedirection from the shield 31 toward the magnetic pole 30) of the secondnonmagnetic layer 22 and the fourth nonmagnetic layer 24 each are notless than 1 nm and not more than 3 nm. The fifth nonmagnetic layer 25and the sixth nonmagnetic layer 26 include, for example, at least oneselected from the group consisting of Cu, Ag, Au, Al, Ti, and Ru. Thethicknesses along the first direction D1 of the fifth nonmagnetic layer25 and the sixth nonmagnetic layer 26 each are not less than 1 nm andnot more than 3 nm. At least one of the fifth nonmagnetic layer 25 orthe sixth nonmagnetic layer 26 may be provided. For example, theincrease of the damping in the first magnetic layer 11 is suppressed.For example, the increase of the damping in the second magnetic layer 12is suppressed. For example, the operating current density decreases. Forexample, a long life is obtained.

In the magnetic head 120, for example, the first magnetic layer 11contacts the first nonmagnetic layer 21 and the fifth nonmagnetic layer25. The second nonmagnetic layer 22 contacts the fifth nonmagnetic layer25 and the sixth nonmagnetic layer 26. The second magnetic layer 12contacts the sixth nonmagnetic layer 26 and the third nonmagnetic layer23. The third magnetic layer 13 contacts the third nonmagnetic layer 23and the fourth nonmagnetic layer 24.

FIG. 4 is a schematic cross-sectional view illustrating the magnetichead and the magnetic recording device according to the secondembodiment.

As shown in FIG. 4, the magnetic recording device 150 in the embodimentincludes a magnetic head 121, the magnetic recording medium 80, and thecircuit portion 10U. For example, the magnetic recording device 150 mayfurther include a recording current circuit (the third circuit 30D).

The magnetic head 121 includes the shield 31, the magnetic pole 30, thefirst to third magnetic layers 11 to 13, and the first to fourthnonmagnetic layers 21 to 24. In the example, the magnetic head 120further includes the fifth nonmagnetic layer 25 and the sixthnonmagnetic layer 26.

In the magnetic head 121, the first magnetic layer 11 is providedbetween the shield 31 and the magnetic pole 30. The second magneticlayer 12 is provided between the first magnetic layer 11 and themagnetic pole 30. The third magnetic layer 13 is provided between thefirst magnetic layer 11 and the second magnetic layer 12.

The first nonmagnetic layer 21 is provided between the shield 31 and thefirst magnetic layer 11. The second nonmagnetic layer 22 is providedbetween the first magnetic layer 11 and the third magnetic layer 13. Thethird nonmagnetic layer 23 is provided between the third magnetic layer13 and the second magnetic layer 12. The fourth nonmagnetic layer 24 isprovided between the second magnetic layer 12 and the magnetic pole 30.The fifth nonmagnetic layer 25 is provided between the first magneticlayer 11 and the second nonmagnetic layer 22. The sixth nonmagneticlayer 26 is provided between the second nonmagnetic layer 22 and thethird magnetic layer 13.

In the example as well, the circuit portion 10U includes the firstcircuit 10D configured to supply the first current I1 and the secondcircuit 20D configured to supply the second current I2. The firstcurrent I1 has an orientation from the first nonmagnetic layer 21 towardthe second nonmagnetic layer 22. The second current I2 has anorientation from the fourth nonmagnetic layer 24 toward the secondnonmagnetic layer 22. The circuit portion 10U is configured to controlthe first current I1 and the second current I2 independently from eachother.

For example, the oscillation frequency of the STO can be adjusted easilyby the second current I2 while reducing the gap magnetic field by thefirst current I1. The recording density can be increased easily. Forexample, a magnetic head and a magnetic recording device can be providedin which the recording density can be increased. The adjustment of theoscillation frequency is easy.

In the magnetic head 121, the first nonmagnetic layer 21 and the thirdnonmagnetic layer 23 include, for example, at least one selected fromthe group consisting of Cu, Ag, Au, Al, and Ti. The second nonmagneticlayer 22 and the fourth nonmagnetic layer 24 include at least oneselected from the group consisting of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd,and Ru. The thicknesses (the thicknesses along the direction from theshield 31 toward the magnetic pole 30) of the second nonmagnetic layer22 and the fourth nonmagnetic layer 24 each are not less than 1 nm andnot more than 3 nm. The fifth nonmagnetic layer 25 and the sixthnonmagnetic layer include at least one selected from the groupconsisting of Cu, Ag, Au, Al, Ti, and Ru. The thicknesses (thethicknesses along the first direction D1) of the fifth nonmagnetic layer25 and the sixth nonmagnetic layer 26 each are not less than 1 nm andnot more than 3 nm. At least one of the fifth nonmagnetic layer 25 orthe sixth nonmagnetic layer 26 may be provided. For example, theincrease of the damping in the first magnetic layer 11 is suppressed.For example, the increase of the damping in the second magnetic layer 12is suppressed. For example, the operating current density decreases. Forexample, a long life is obtained.

In the magnetic head 121, for example, the first magnetic layer 11contacts the first nonmagnetic layer 21 and the fifth nonmagnetic layer25. The second nonmagnetic layer 22 contacts the fifth nonmagnetic layer25 and the sixth nonmagnetic layer 26. The third magnetic layer 13contacts the sixth nonmagnetic layer 26 and the third nonmagnetic layer23. The second magnetic layer 12 contacts the third nonmagnetic layer 23and the fourth nonmagnetic layer 24.

In the magnetic heads 120 and 121, for example, the product of thethickness (the thickness along the first direction D1) of the secondmagnetic layer 12 and the second saturation magnetic flux density of thesecond magnetic layer 12 is larger than the product of the thickness(the thickness along the first direction D1) of the third magnetic layerand the third saturation magnetic flux density of the third magneticlayer 13. Thereby, the oscillation occurs easily in the second magneticlayer 12. For example, the product of the volume of the second magneticlayer 12 and the second saturation magnetic flux density of the secondmagnetic layer 12 is larger than the product of the volume of the thirdmagnetic layer 13 and the third saturation magnetic flux density of thethird magnetic layer 13. For example, the thickness of the thirdmagnetic layer 13 is thinner than the thickness of the second magneticlayer 12. Thereby, for example, stable oscillation is obtained in thesecond magnetic layer 12 and the third magnetic layer 13.

Third Embodiment

FIG. 5 is a schematic cross-sectional view illustrating a magnetic headand a magnetic recording device according to a third embodiment.

In the embodiment as shown in FIG. 5, the magnetic recording device 150includes the magnetic head 130, the magnetic recording medium 80, andthe circuit portion 10U. For example, the magnetic recording device 150may further include a recording current circuit (the third circuit 30D).

The magnetic head 130 includes the shield 31, the magnetic pole 30, thefirst to third magnetic layers 11 to 13, and the first to fourthnonmagnetic layers 21 to 24. In the example, the magnetic head 130further includes the fifth nonmagnetic layer 25 and the sixthnonmagnetic layer 26.

The magnetic pole 30 has the medium-opposing surface 30F. The firstdirection D1 from the shield 31 toward the magnetic pole 30 is along themedium-opposing surface 30F. For example, the medium-opposing surface30F is along the X-Y plane.

The position in the first direction D1 of the first magnetic layer 11 isbetween the position in the first direction D1 of the shield 31 and theposition in the first direction D1 of the magnetic pole 30.

The second magnetic layer 12 is provided between the shield 31 and themagnetic pole 30. A direction crossing the medium-opposing surface 30Fis taken as a second direction D2. For example, the second direction D2is aligned with the Z-axis direction. The position in the seconddirection D2 of the second magnetic layer 12 is between the position inthe second direction D2 of a plane (a plane along the X-Y plane)including the medium-opposing surface 30F and the position in the seconddirection D2 of the first magnetic layer 11.

The third magnetic layer 13 is provided between the second magneticlayer 12 and the magnetic pole 30.

The first nonmagnetic layer 21 is provided between the first magneticlayer 11 and the magnetic pole 30. The second nonmagnetic layer 22 isprovided between the shield 31 and the second magnetic layer 12. Thethird nonmagnetic layer 23 is provided between the second magnetic layer12 and the third magnetic layer 13. The fourth nonmagnetic layer 24 isprovided between the third magnetic layer 13 and the magnetic pole 30.The first magnetic layer 11 is provided between the fifth nonmagneticlayer 25 and the firSt nonmagnetic layer 21. The sixth nonmagnetic layer26 is provided between the second nonmagnetic layer 22 and the secondmagnetic layer 12.

In the magnetic head 130, the first magnetic layer 11 is providedseparately from the stacked body including the second magnetic layer 12and the third magnetic layer 13. The first current I1 that flows in thefirst magnetic layer 11 and the second current I2 that flows in thestacked body including the second magnetic layer 12 and the thirdmagnetic layer 13 are controllable independently from each other.

In the magnetic head 130, the first magnetic layer magnetization 11M isreversed with respect to the orientations of the shield magnetization31M and the magnetic pole magnetization 30M by the first current I1flowing in the first magnetic layer 11. The gap magnetic fieldincreases.

For example, the oscillation frequency of the STO can be adjusted easilyby the second current I2 flowing in the stacked body including thesecond magnetic layer 12 and the third magnetic layer 13 whileincreasing the gap magnetic field by the first current IL The recordingdensity can be increased easily. For example, a magnetic head and amagnetic recording device can be provided in which the recording densitycan be increased. The adjustment of the oscillation frequency is easy.

The magnetic recording device 150 that includes the magnetic head 130may include the circuit portion 10U. The circuit portion 10U includesthe first circuit 10D configured to supply the first current I1 and thesecond circuit 20D configured to supply the second current I2. The firstcurrent I1 has an orientation from the first magnetic layer 11 towardthe first nonmagnetic layer 21. The first current I1 has an orientationfrom the magnetic pole 30 toward the first nonmagnetic layer 21. Thesecond current I2 has an orientation from the second nonmagnetic layer22 toward the fourth nonmagnetic layer 24. The second current I2 has anorientation from the shield 31 toward the magnetic pole 30. The circuitportion 10U is configured to control the first current I1 and the secondcurrent I2 independently from each other.

A conductive layer 20 e is provided in the example. The firstnonmagnetic layer 21 is between the conductive layer 20 e and the firstmagnetic layer 11.

For example, the magnetic head 130 includes the first to third terminalsT1 to T3. The first terminal T1 is electrically connected to the shield31. The second terminal T2 is electrically connected to the magneticpole 30. The third terminal T3 is electrically connected to theconductive layer 20 e.

One end of the second circuit 20D is electrically connected to the firstterminal T1. The other end of the second circuit 20D is electricallyconnected to the third terminal T3. One end of the first circuit 10D iselectrically connected to the second terminal T2. The other end of thefirst circuit 10D is electrically connected to the third terminal T3.

In the magnetic head 130, the first nonmagnetic layer 21 and the thirdnonmagnetic layer 23 include, for example, at least one selected fromthe group consisting of Cu, Ag, Au, Al, and Ti. The second nonmagneticlayer 22 and the fourth nonmagnetic layer include at least one selectedfrom the group consisting of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru.The thicknesses along the first direction D1 (the direction from theshield 31 toward the magnetic pole 30) of the second nonmagnetic layer22 and the fourth nonmagnetic layer 24 each are not less than 1 nm andnot more than 3 nm. The fifth nonmagnetic layer 25 and the sixthnonmagnetic layer 26 include at least one selected from the groupconsisting of Cu, Ag, Au, Al, Ti, and Ru. The thicknesses along thefirst direction D1 of the fifth nonmagnetic layer 25 and the sixthnonmagnetic layer 26 each are not less than 1 nm and not more than 3 nm.At least one of the fifth nonmagnetic layer 25 or the sixth nonmagneticlayer 26 may be provided. For example, the increase of the damping inthe first magnetic layer 11 is suppressed. For example, the increase ofthe damping in the second magnetic layer 12 is suppressed. For example,the operating current density decreases. For example, a long life isobtained.

In the magnetic head 130, for example, the first magnetic layer 11contacts the first nonmagnetic layer 21 and the fifth nonmagnetic layer25. The sixth nonmagnetic layer 26 contacts the second nonmagnetic layer22 and the second magnetic layer 12. The second magnetic layer 12contacts the sixth nonmagnetic layer 26 and the third nonmagnetic layer23. The third magnetic layer 13 contacts the third nonmagnetic layer 23and the fourth nonmagnetic layer 24.

FIG. 6 is a schematic cross-sectional view illustrating the magnetichead and the magnetic recording device according to the thirdembodiment.

In the embodiment as shown in FIG. 6, the magnetic recording device 150includes a magnetic head 131, the magnetic recording medium 80, and thecircuit portion 10U. For example, the magnetic recording device 150 mayfurther include a recording current circuit (the third circuit 30D).

The magnetic head 131 includes the shield 31, the magnetic pole 30, thefirst to third magnetic layers 11 to 13, and the first to fourthnonmagnetic layers 21 to 24. In the example, the magnetic head 131further includes the fifth nonmagnetic layer 25 and the sixthnonmagnetic layer 26.

The first direction D1 from the shield 31 toward the magnetic pole 30 isalong the medium-opposing surface 30F of the magnetic pole 30. Theposition in the first direction D1 of the first magnetic layer 11 isbetween the position in the first direction D1 of the shield 31 and theposition in the first direction D1 of the magnetic pole 30.

The second magnetic layer 12 is provided between the shield 31 and themagnetic pole 30. The position of the second magnetic layer 12 in thesecond direction D2 crossing the medium-opposing surface 30F is betweenthe position in the second direction D2 of the first magnetic layer 11and the position in the second direction D2 of a plane including themedium-opposing surface 30F.

The third magnetic layer 13 is provided between the shield 31 and thesecond magnetic layer 12.

The first nonmagnetic layer 21 is provided between the first magneticlayer 11 and the magnetic pole 30. The second nonmagnetic layer 22 isprovided between the second magnetic layer 12 and the magnetic pole 30.The third nonmagnetic layer 23 is provided between the third magneticlayer 13 and the second magnetic layer 12. The fourth nonmagnetic layer24 is provided between the shield 31 and the third magnetic layer 13.The first magnetic layer 11 is provided between the fifth nonmagneticlayer 25 and the first nonmagnetic layer 21. The sixth nonmagnetic layer26 is provided between the second nonmagnetic layer 22 and the secondmagnetic layer 12.

In the magnetic head 131 as well, the first magnetic layer 11 isprovided separately from the stacked body including the second magneticlayer 12 and the third magnetic layer 13. The first current I1 thatflows in the first magnetic layer 11 and the second current I2 thatflows in the stacked body including the second magnetic layer 12 and thethird magnetic layer 13 are controllable independently from each other.The first current I1 has an orientation from the first magnetic layer 11toward the first nonmagnetic layer 21. The second current I2 has anorientation from the second nonmagnetic layer 22 toward the fourthnonmagnetic layer 24.

In the magnetic head 131, the first magnetic layer magnetization 11M isreversed with respect to the orientations of the shield magnetization31M and the magnetic pole magnetization 30M by the first current I1flowing in the first magnetic layer 11. The gap magnetic fieldincreases.

For example, the oscillation frequency of the STO can be adjusted easilyby the second current I2 flowing in the stacked body including thesecond magnetic layer 12 and the third magnetic layer 13 whileincreasing the gap magnetic field by the first current IL The recordingdensity can be increased easily. For example, a magnetic head and amagnetic recording device can be provided in which the recording densitycan be increased. The adjustment of the oscillation frequency is easy.

For example, the magnetic head 131 includes the first to third terminalsT1 to T3. The third terminal T3 is electrically connected to theconductive layer 20 e. The second circuit 20D is electrically connectedto the first terminal T1 and the third terminal T3. The first circuit10D is electrically connected to the second terminal T2 and the thirdterminal T3.

In the magnetic head 131, the first nonmagnetic layer 21 and the thirdnonmagnetic layer 23 include, for example, at least one selected fromthe group consisting of Cu, Ag, Au, Al, and Ti. The second nonmagneticlayer 22 and the fourth nonmagnetic layer 24 include at least oneselected from the group consisting of Ta, Pt, Ir, W, Mo, Cr, Tb, Rh, Pd,and Ru. The thicknesses along the first direction D1 of the secondnonmagnetic layer 22 and the fourth nonmagnetic layer 24 each are notless than 1 nm and not more than 3 nm. The fifth nonmagnetic layer 25and the sixth nonmagnetic layer 26 include at least one selected fromthe group consisting of Cu, Ag, Au, Al, Ti, and Ru. The thicknessesalong the first direction D1 of the fifth nonmagnetic layer 25 and thesixth nonmagnetic layer 26 each are not less than 1 nm and not more than3 nm. At least one of the fifth nonmagnetic layer 25 or the sixthnonmagnetic layer 26 may be provided. For example, the increase of thedamping in the first magnetic layer 11 is suppressed. For example, theincrease of the damping in the second magnetic layer 12 is suppressed.For example, the operating current density decreases. For example, along life is obtained.

In the magnetic head 131, for example, the first magnetic layer 11contacts the first nonmagnetic layer 21 and the fifth nonmagnetic layer25. The third magnetic layer 13 contacts the fourth nonmagnetic layer 24and the third nonmagnetic layer 23. The second magnetic layer 12contacts the third nonmagnetic layer 23 and the sixth nonmagnetic layer26. The sixth nonmagnetic layer 26 contacts the second magnetic layer 12and the second nonmagnetic layer 22.

In the magnetic heads 130 and 131, for example, the product of thethickness (the thickness along the first direction D1) of the secondmagnetic layer 12 and the second saturation magnetic flux density of thesecond magnetic layer 12 is larger than the product of the thickness(the thickness along the first direction D1) of the third magnetic layer13 and the third saturation magnetic flux density of the third magneticlayer 13. Thereby, the oscillation occurs easily in the second magneticlayer 12. For example, the product of the volume of the second magneticlayer 12 and the second saturation magnetic flux density of the secondmagnetic layer 12 is larger than the product of the volume of the thirdmagnetic layer 13 and the third saturation magnetic flux density of thethird magnetic layer 13. For example, the thickness of the thirdmagnetic layer 13 is thinner than the thickness of the second magneticlayer 12. Thereby, for example, stable oscillation is obtained in thesecond magnetic layer 12 and the third magnetic layer 13.

In the magnetic head 130, the distance along the second direction D2between the second magnetic layer 12 and the first magnetic layer 11 is,for example, not less than ½ of the length along the second direction D2of the first magnetic layer 11. In the magnetic head 131, the distancealong the second direction D2 between the third magnetic layer 13 andthe first magnetic layer 11 is, for example, not less than 1/2 of thelength along the second direction D2 of the first magnetic layer 11.

FIG. 7 and FIG. 8 are schematic cross-sectional views illustrating themagnetic head and the magnetic recording device according to theembodiment.

As in a magnetic head 140 illustrated in FIG. 7, the stacking directionof the stacked body SB (the first direction D1) may be tilted withrespect to a plane (e.g., the X-Y plane) including the medium-opposingsurface 30F in the configuration of the magnetic head 110. As in amagnetic head 141 illustrated in FIG. 8, the stacking direction of thestacked body SB may be tilted with respect to a plane (e.g., the X-Yplane) including the medium-opposing surface 30F in the configuration ofthe magnetic head 111. In the magnetic head 141, the volume of thesecond magnetic layer 12 is easily set to be larger than the volume ofthe third magnetic layer 13.

Such a tilt of the stacking direction (the first direction D1) isapplicable to any magnetic recording head according to the first tothird embodiments.

In the embodiment, the magnetic pole 30 includes, for example, an FeCoalloy, an FeCoNi alloy, etc.

The shield 31 includes, for example, an FeCo alloy, an FeCoNi alloy,etc.

At least one of the second magnetic layer 12 or the third magnetic layer13 includes, for example, at least one of an FeCo alloy, a Heusleralloy, a [Fe/Co] artificial lattice, a [FeCoNi/Ni] artificial lattice,or a [Co/Pt] artificial lattice. At least one of the first magneticlayer 11 or the second magnetic layer 12 may include a stacked filmincluding at least two of an FeCo alloy film, a Heusler alloy film, a[Fe/Co] artificial lattice film, a [FeCoNi/Ni] artificial lattice film,or a [Co/Pt] artificial lattice film.

The magnetic recording medium 80 includes, for example, a CoCrPt—SiO₂granular film.

The magnetic head according to the embodiment may perform shingledrecording or interlaced recording to the magnetic recording medium 80.The recording density can be increased further.

An example of a magnetic recording device according to the embodimentwill now be described.

FIG. 9 is a schematic perspective view illustrating a portion of themagnetic recording device according to the embodiment.

FIG. 9 illustrates a head slider.

The magnetic head 110 is provided in the head slider 159. The headslider 159 includes, for example, Al₂O₃/TiC, etc. The head slider 159moves relative to the magnetic recording medium while flying over orcontacting the magnetic recording medium.

The head slider 159 has, for example, an air inflow side 159A and an airoutflow side 159B. The magnetic head 110 is disposed at the side surfaceof the air outflow side 159B of the head slider 159 or the like.Thereby, the magnetic head 110 moves relative to the magnetic recordingmedium while flying over or contacting the magnetic recording medium.

FIG. 10 is a schematic perspective view illustrating the magneticrecording device according to the embodiment.

As shown in FIG. 10, a rotary actuator is used in the magnetic recordingdevice 150 according to the embodiment. A recording medium disk 180 isprovided in a spindle motor 180M. The recording medium disk 180 isrotated in the direction of arrow AR by the spindle motor 180M. Thespindle motor 180M responds to a control signal from a drive devicecontroller. The magnetic recording device 150 according to theembodiment may include multiple recording medium disks 180. The magneticrecording device 150 may include a recording medium 181. The recordingmedium 181 is, for example, a SSD (Solid State Drive). The recordingmedium 181 includes, for example, nonvolatile memory such as flashmemory, etc. For example, the magnetic recording device 150 may be ahybrid HDD (Hard Disk Drive).

The head slider 159 records and reproduces the information recorded inthe recording medium disk 180. The head slider 159 is provided at thetip of a suspension 154 having a thin-film configuration. The magnetichead according to the embodiment is provided at the tip vicinity of thehead slider 159.

When the recording medium disk 180 rotates, the downward pressure due tothe suspension 154 and the pressure generated by the medium-opposingsurface (the ABS) of the head slider 159 are balanced. The distancebetween the medium-opposing surface of the head slider 159 and thesurface of the recording medium disk 180 becomes a prescribed flyheight. In the embodiment, the head slider 159 may contact the recordingmedium disk 180. For example, contact-sliding is applicable.

The suspension 154 is connected to one end of an arm 155 (e.g., anactuator arm). The arm 155 includes, for example, a bobbin part, etc.The bobbin part holds a drive coil. A voice coil motor 156 is providedat the other end of the arm 155. The voice coil motor 156 is one type oflinear motor. The voice coil motor 156 includes, for example, the drivecoil and a magnetic circuit. The drive coil is wound onto the bobbinpart of the arm 155. The magnetic circuit includes a permanent magnetand an opposing yoke. The drive coil is provided between the permanentmagnet and the opposing yoke. The suspension 154 has one end and anotherend. The magnetic head is provided at the one end of the suspension 154.The arm 155 is connected to the other end of the suspension 154.

The arm 155 is held by ball bearings. The ball bearings are provided attwo locations above and below a bearing part 157. The arm 155 can rotateand slide due to the voice coil motor 156. The magnetic head is movableto any position of the recording medium disk 180.

FIG. 11A and FIG. 11B are schematic perspective views illustrating aportion of the magnetic recording device according to the embodiment.

FIG. 11A illustrates the configuration of a portion of the magneticrecording device and is an enlarged perspective view of a head stackassembly 160. FIG. 11B is a perspective view illustrating a magnetichead assembly (a head gimbal assembly (HGA)) 158 that is a portion ofthe head stack assembly 160.

As shown in FIG. 11A, the head stack assembly 160 includes the bearingpart 157, the head gimbal assembly 158, and a support frame 161. Thehead gimbal assembly 158 extends from the bearing part 157. The supportframe 161 extends from the bearing part 157. The direction in which thesupport frame 161 extends is the reverse of the direction in which thehead gimbal assembly 158 extends. The support frame 161 supports a coil162 of the voice coil motor 156.

As shown in FIG. 11B, the head gimbal assembly 158 includes the arm 155extending from the bearing part 157 and the suspension 154 extendingfrom the arm 155.

The head slider 159 is provided at the tip of the suspension 154. Themagnetic head according to the embodiment is provided at the head slider159.

The magnetic head assembly (the head gimbal assembly) 158 according tothe embodiment includes the magnetic head according to the embodiment,the head slider 159 on which the magnetic head is provided, thesuspension 154, and the arm 155. The head slider 159 is provided at oneend of the suspension 154. The arm 155 is connected to the other end ofthe suspension 154.

The suspension 154 includes, for example, lead wires (not illustrated)for recording and reproducing signals. The suspension 154 may include,for example, lead wires (not illustrated) for a heater that adjusts thefly height. The suspension 154 may include, for example, lead wires (notillustrated) for a spin torque oscillator, etc. These lead wires areelectrically connected to multiple electrodes provided in the magnetichead.

A signal processor 190 is provided in the magnetic recording device 150.The signal processor 190 records and reproduces the signals to and fromthe magnetic recording medium by using the magnetic head. For example,the signal processor 190 is electrically connected to the magnetic headby the input/output lines of the signal processor 190 being connected toelectrode pads of the head gimbal assembly 158.

The magnetic recording device 150 according to the embodiment includes amagnetic recording medium, the magnetic head according to theembodiment, a movable part, a position controller, and a signalprocessor. The movable part causes the magnetic recording medium and themagnetic head to separate or causes the magnetic recording medium andthe magnetic head to be movable relative to each other in a state ofcontact. The position controller aligns the magnetic head, at aprescribed recording position of the magnetic recording medium. Thesignal processor records and reproduces the signals to and from themagnetic recording medium by using the magnetic head.

For example, the recording medium disk 180 is used as the magneticrecording medium recited above. The movable part recited above includes,for example, the head slider 159. The position controller recited aboveincludes, for example, the head gimbal assembly 158.

The magnetic recording device 150 according to the embodiment includes amagnetic recording medium, the magnetic head assembly according to theembodiment, and a signal processor that records and reproduces thesignals to and from the magnetic recording medium by using the magnetichead provided in the magnetic head assembly.

The embodiments may include the following configurations (e.g.,technological proposals).

Configuration 1

A magnetic head, comprising:

a shield;

a magnetic pole;

a first magnetic layer provided between the shield and the magneticpole;

a second magnetic layer provided between the first magnetic layer andthe magnetic pole;

a third magnetic layer provided between the second magnetic layer andthe magnetic pole;

a first nonmagnetic layer provided between the shield and the firstmagnetic layer;

a second nonmagnetic layer provided between the first magnetic layer andthe second magnetic layer;

a third nonmagnetic layer provided between the second magnetic layer andthe third magnetic layer; and

a fourth nonmagnetic layer provided between the third magnetic layer andthe magnetic pole,

the first nonmagnetic layer and the third nonmagnetic layer including atleast one selected from the group consisting of Cu, Ag, Au, Al, and Ti,

the second nonmagnetic layer and the fourth nonmagnetic layer includingat least one selected from the group consisting of Ta, Pt, Ir, W, Mo,Cr, Tb, Rh, Pd, and Ru,

thicknesses along a first direction of the second nonmagnetic layer andthe fourth nonmagnetic layer each being not less than 1 nm and not morethan 3 nm, the first direction being from the shield toward the magneticpole.

Configuration 2

The magnetic head according to Configuration 1, wherein a first currenthaving an orientation from the first nonmagnetic layer toward the fourthnonmagnetic layer flows.

Configuration 3

A magnetic head, comprising:

a shield;

a magnetic pole;

a first magnetic layer provided between the shield and the magneticpole;

a second magnetic layer provided between the shield and the firstmagnetic layer;

a third magnetic layer provided between the shield and the secondmagnetic layer;

a first nonmagnetic layer provided between the first magnetic layer andthe magnetic pole;

a second nonmagnetic layer provided between the second magnetic layerand the first nonmagnetic layer;

a third nonmagnetic layer provided between the third magnetic layer andthe second nonmagnetic layer; and

a fourth nonmagnetic layer provided between the shield and the thirdmagnetic layer,

the first nonmagnetic layer and the third nonmagnetic layer including atleast one selected from the group consisting of Cu, Ag, Au, Al, and Ti,

the second nonmagnetic layer and the fourth nonmagnetic layer includingat least one selected from the group consisting of Ta, Pt, Ir, W, Mo,Cr, Tb, Rh, Pd, and Ru,

thicknesses along a first direction of the second nonmagnetic layer andthe fourth nonmagnetic layer each being not less than 1 nm and not morethan 3 nm, the first direction being from the shield toward the magneticpole.

Configuration 4

The magnetic head according to Configuration 3, wherein a first currenthaving an orientation from the first nonmagnetic layer toward the fourthnonmagnetic layer flows.

Configuration 5

The magnetic head according to any one of Configurations 1 to 4, furthercomprising:

a fifth nonmagnetic layer provided between the second nonmagnetic layerand the first magnetic layer; and

a sixth nonmagnetic layer provided between the second magnetic layer andthe second nonmagnetic layer,

the fifth nonmagnetic layer and the sixth nonmagnetic layer including atleast one selected from the group consisting of Cu, Ag, Au, Al, Ti, andRu,

thicknesses along the first direction of the fifth nonmagnetic layer andthe sixth nonmagnetic layer each being not less than 1 nm and not morethan 3 nm.

Configuration 6

A magnetic head, comprising:

a shield;

a magnetic pole having a medium-opposing surface, a first direction fromthe shield toward the magnetic pole being along the medium-opposingsurface;

a first magnetic layer, a position in the first direction of the firstmagnetic layer being between a position in the first direction of theshield and a position in the first direction of the magnetic pole,

a second magnetic layer provided between the shield and the magneticpole, a position of the second magnetic layer in a second directionbeing between a position in the second direction of the first magneticlayer and a position in the second direction of a plane including themedium-opposing surface, the second direction crossing themedium-opposing surface;

a third magnetic layer provided between the second magnetic layer andthe magnetic pole;

a first nonmagnetic layer provided between the first magnetic layer andthe magnetic pole;

a second nonmagnetic layer provided between the shield and the secondmagnetic layer;

a third nonmagnetic layer provided between the second magnetic layer andthe third magnetic layer;

a fourth nonmagnetic layer provided between the third magnetic layer andthe magnetic pole;

a fifth nonmagnetic layer, the first magnetic layer being providedbetween the fifth nonmagnetic layer and the first nonmagnetic layer; and

a sixth nonmagnetic layer provided between the second nonmagnetic layerand the second magnetic layer.

Configuration 7

A magnetic head, comprising:

a shield;

a magnetic pole having a medium-opposing surface, a first direction fromthe shield toward the magnetic pole being along the medium-opposingsurface;

a first magnetic layer, a position in the first direction of the firstmagnetic layer being between a position in the first direction of theshield and a position in the first direction of the magnetic pole;

a second magnetic layer provided between the shield and the magneticpole, a position of the second magnetic layer in a second directionbeing between a position in the second direction of the first magneticlayer and a position in the second direction of a plane including themedium-opposing surface, the second direction crossing themedium-opposing surface;

a third magnetic layer provided between the shield and the secondmagnetic layer;

a first nonmagnetic layer provided between the first magnetic layer andthe magnetic pole;

a second nonmagnetic layer provided between the second magnetic layerand the magnetic pole;

a third nonmagnetic layer provided between the third magnetic layer andthe second magnetic layer;

a fourth nonmagnetic layer provided between the shield and the thirdmagnetic layer;

a fifth nonmagnetic layer, the first magnetic layer being providedbetween the fifth nonmagnetic layer and the first nonmagnetic layer; and

a sixth nonmagnetic layer provided between the second magnetic layer andthe second nonmagnetic layer.

Configuration 8

The magnetic head according to Configuration 6 or 7, wherein

the first nonmagnetic layer and the third nonmagnetic layer include atleast one selected from the group consisting of Cu, Ag, Au, Al, and Ti,

the second nonmagnetic layer and the fourth nonmagnetic layer include atleast one selected from the group consisting of Ta, Pt, Ir, W, Mo, Cr,Tb, Rh, Pd, and Ru,

thicknesses along a first direction of the second nonmagnetic layer andthe fourth nonmagnetic layer each are not less than 1 nm and not morethan 3 nm, the first direction being from the shield toward the magneticpole,

the fifth nonmagnetic layer and the sixth nonmagnetic layer include atleast one selected from the group consisting of Cu, Ag, Au, Al, Ti, andRu, and

thicknesses along the first direction of the fifth nonmagnetic layer andthe sixth nonmagnetic layer each are not less than 1 nm and not morethan 3 nm.

Configuration 9

The magnetic head according to any one of Configurations 1 to 8, whereina product of a second thickness along the first direction of the secondmagnetic layer and a second saturation magnetic flux density of thesecond magnetic layer is larger than a product of a third thicknessalong the first direction of the third magnetic layer and a thirdsaturation magnetic flux density of the third magnetic layer.

Configuration 10

The magnetic head according to any one of Configurations 1 to 9, whereina product of a volume of the second magnetic layer and a secondsaturation magnetic flux density of the second magnetic layer is largerthan a product of a volume of the third magnetic layer and a thirdsaturation magnetic flux density of the third magnetic layer.

Configuration 11

A magnetic recording device, comprising:

the magnetic head according to any one of Configurations 6 to 8; and

a circuit portion,

the circuit portion including

-   -   a first circuit configured to supply a first current having an        orientation from the first magnetic layer toward the first        nonmagnetic layer, and    -   a second circuit configured to supply a second current having an        orientation from the second nonmagnetic layer toward the fourth        nonmagnetic layer,

the circuit portion being configured to control the first current andthe second current independently from each other.

Configuration 12

A magnetic recording device, comprising:

a shield;

a magnetic pole;

a first magnetic layer provided between the shield and the magneticpole;

a second magnetic layer provided between the first magnetic layer andthe magnetic pole;

a third magnetic layer provided between the second magnetic layer andthe magnetic pole;

a first nonmagnetic layer provided between the shield and the firstmagnetic layer;

a second nonmagnetic layer provided between the first magnetic layer andthe second magnetic layer;

a third nonmagnetic layer provided between the second magnetic layer andthe third magnetic layer;

a fourth nonmagnetic layer provided between the third magnetic layer andthe magnetic pole; and

a circuit portion including a first circuit and a second circuit, thefirst circuit being configured to supply a first current having anorientation from the first nonmagnetic layer toward the secondnonmagnetic layer, the second circuit being configured to supply asecond current having an orientation from the second nonmagnetic layertoward the fourth nonmagnetic layer,

the circuit portion being configured to control the first current andthe second current independently from each other.

Configuration 13

The magnetic recording device according to Configuration 12, furthercomprising:

a fifth nonmagnetic layer provided between the first magnetic layer andthe second nonmagnetic layer; and

a sixth nonmagnetic layer provided between the second nonmagnetic layerand the second magnetic layer,

the fifth nonmagnetic layer and the sixth nonmagnetic layer including atleast one selected from the group consisting of Cu, Ag, Au, Al, Ti, andRu.

thicknesses along the first direction of the fifth nonmagnetic layer andthe sixth nonmagnetic layer each being not less than 1 nm and not morethan 3 nm.

Configuration 14

A magnetic recording device, comprising:

a shield;

a magnetic pole;

a first magnetic layer provided between the shield and the magneticpole;

a second magnetic layer provided between the first magnetic layer andthe magnetic pole;

a third magnetic layer provided between the first magnetic layer and thesecond magnetic layer;

a first nonmagnetic layer provided between the shield and the firstmagnetic layer;

a second nonmagnetic layer provided between the first magnetic layer andthe third magnetic layer;

a third nonmagnetic layer provided between the third magnetic layer andthe second magnetic layer;

a fourth nonmagnetic layer provided between the second magnetic layerand the magnetic pole; and

a circuit portion including a first circuit and a second circuit, thefirst circuit being configured to supply a first current having anorientation from the first nonmagnetic layer toward the secondnonmagnetic layer, the second circuit being configured to supply asecond current having an orientation from the fourth nonmagnetic layertoward the second nonmagnetic layer,

the circuit portion being configured to control the first current andthe second current independently from each other.

Configuration 15

The magnetic recording device according to Configuration 14, furthercomprising:

a fifth nonmagnetic layer provided between the first magnetic layer andthe second nonmagnetic layer; and

a sixth nonmagnetic layer provided between the second nonmagnetic layerand the third magnetic layer,

the fifth nonmagnetic layer and the sixth nonmagnetic layer including atleast one selected from the group consisting of Cu, Ag, Au, Al, Ti, andRu,

thicknesses along the first direction of the fifth nonmagnetic layer andthe sixth nonmagnetic layer each being not less than 1 nm and not morethan 3 nm.

Configuration 16

The magnetic recording device according to any one of Configurations 12to 15, wherein

the first nonmagnetic layer and the third nonmagnetic layer include atleast one selected from the group consisting of Cu, Ag, Au, Al, and Ti,

the second nonmagnetic layer and the fourth nonmagnetic layer include atleast one selected from the group consisting of Ta, Pt, Ir, W, Mo, Cr,Tb, Rh, Pd, and Ru, and

thicknesses along a first direction of the second nonmagnetic layer andthe fourth nonmagnetic layer each are not less than 1 nm and not morethan 3 nm, the first direction being from the shield toward the magneticpole.

Configuration 17

The magnetic recording device according to any one of Configurations 12to 16, wherein a product of a second thickness along the first directionof the second magnetic layer and a second saturation magnetic fluxdensity of the second magnetic layer is larger than a product of a thirdthickness along the first direction of the third magnetic layer and athird saturation magnetic flux density of the third magnetic layer.

Configuration 18

The magnetic recording device according to any one of Configurations 12to 17, wherein a product of a volume of the second magnetic layer and asecond saturation magnetic flux density of the second magnetic layer islarger than a product of a volume of the third magnetic layer and athird saturation magnetic flux density of the third magnetic layer.

Configuration 19

The magnetic recording device according to any one of Configurations 12to 18, wherein the first magnetic layer includes at least one selectedfrom the group consisting of FeNi and CoFe.

Configuration 20

The magnetic recording device according to any one of Configurations 12to 19, further comprising a third circuit,

the magnetic head further including a coil,

the third circuit supplying a recording current to the coil.

Configuration 21

The magnetic head according to any one of Configurations 1 to 10,wherein a thickness of the second magnetic layer is thinner than athickness of the third magnetic layer.

Configuration 22

The magnetic recording device according to any one of Configurations 12to 20, wherein a thickness of the second magnetic layer is thinner thana thickness of the third magnetic layer.

According to the embodiments, a magnetic head and a magnetic recordingdevice can be provided in which the recording density can be increased.

In the specification of the application, “perpendicular” and “parallel”refer to not only strictly perpendicular and strictly parallel but alsoinclude, for example, the fluctuation due to manufacturing processes,etc. It is sufficient to be substantially perpendicular andsubstantially parallel.

Hereinabove, exemplary embodiments of the invention are described withreference to specific examples. However, the embodiments of theinvention are not limited to these specific examples. For example, oneskilled in the art may similarly practice the invention by appropriatelyselecting specific configurations of components included in magneticheads such as magnetic poles, shields, magnetic layers, conductivelayers, insulating layers, interconnections, etc., from known art. Suchpractice is included in the scope of the invention to the extent thatsimilar effects thereto are obtained.

Further, any two or more components of the specific examples may becombined within the extent of technical feasibility and are included inthe scope of the invention to the extent that the purport of theinvention is included.

Moreover, all magnetic recording devices, and magnetic heads practicableby an appropriate design modification by one skilled in the art based onthe magnetic recording devices, and the magnetic heads described aboveas embodiments of the invention also are within the scope of theinvention to the extent that the purport of the invention is included.

Various other variations and modifications can be conceived by thoseskilled in the art within the spirit of the invention, and it isunderstood that such variations and modifications are also encompassedwithin the scope of the invention.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the invention.

1-2. (canceled)
 3. A magnetic head, comprising: a shield; a magneticpole; a first magnetic layer provided between the shield and themagnetic pole; a second magnetic layer provided between the shield andthe first magnetic layer; a third magnetic layer provided between theshield and the second magnetic layer; a first nonmagnetic layer providedbetween the first magnetic layer and the magnetic pole; a secondnonmagnetic layer provided between the second magnetic layer and thefirst nonmagnetic layer; a third nonmagnetic layer provided between thethird magnetic layer and the second nonmagnetic layer; and a fourthnonmagnetic layer provided between the shield and the third magneticlayer, the first nonmagnetic layer and the third nonmagnetic layerincluding at least one selected from the group consisting of Cu, Ag, Au,Al, and Ti, the second nonmagnetic layer and the fourth nonmagneticlayer including at least one selected from the group consisting of Ta,Pt, Ir, W, Mo, Cr, Tb, Rh, Pd, and Ru, thicknesses along a firstdirection of the second nonmagnetic layer and the fourth nonmagneticlayer each being not less than 1 nm and not more than 3 nm, the firstdirection being from the shield toward the magnetic pole.
 4. Themagnetic head according to claim 3, wherein a first current having anorientation from the first nonmagnetic layer toward the fourthnonmagnetic layer flows.
 5. The magnetic head according to claim 3,further comprising: a fifth nonmagnetic layer provided between thesecond nonmagnetic layer and the first magnetic layer; and a sixthnonmagnetic layer provided between the second magnetic layer and thesecond nonmagnetic layer, the fifth nonmagnetic layer and the sixthnonmagnetic layer including at least one selected from the groupconsisting of Cu, Ag, Au, Al, Ti, and Ru, thicknesses along the firstdirection of the fifth nonmagnetic layer and the sixth nonmagnetic layereach being not less than 1 nm and not more than 3 nm. 6-8. (canceled) 9.The magnetic head according to claim 3, wherein a product of a secondthickness along the first direction of the second magnetic layer and asecond saturation magnetic flux density of the second magnetic layer islarger than a product of a third thickness along the first direction ofthe third magnetic layer and a third saturation magnetic flux density ofthe third magnetic layer.
 10. The magnetic head according to claim 3,wherein a product of a volume of the second magnetic layer and a secondsaturation magnetic flux density of the second magnetic layer is largerthan a product of a volume of the third magnetic layer and a thirdsaturation magnetic flux density of the third magnetic layer. 11-20.(canceled)